We will develop, improve, and maintain a scientific resource of mutant-bearing stocks, incipient-inbred, and inbred strains of rabbits and provide them to research workers at the Jackson Laboratory and elsewhere. The mutant pathologies and genetic uniformity of these rabbits make them valuable for studying vital processes related to constitutional diseases, growth, and reproductive disorders in man. We will accomplish these objectives by inbreeding, by maintenance, by characterization, by collaborative studies, and by distribution to qualified investigators of (1) rabbits with specific genes such as adrenal hyperplasia (ah), ataxia (ax), buphthalmia (bu), audiogenic seizures (ep), chondrodystrophy (cd), osteopetrosis (os), dachs (Da), dwarf (Dw), achondroplasia (ac), spina bifida (sb), hypogonadia (hg), renal cysts (rc), mandibular prognathism (mp), lymphosarcoma (ls), hemolytic anemia (ha), seven genes at three gamma globulin loci, five morphological hair characters, etc., (2) rabbits with abnormalities such as hemiuterus, absent upper incisors, and scoliosis; and (3) rabbit inbred stocks including the B/J stain now in its 27th generation of continuous brother-by-sister mating. We will also collect, analyze, and disseminate data on the morphological, physiological, hematological, biochemical, and vital characteristics of these stocks. A Handbook on Genetically Standardized JAX Rabbits is now available.